GB2177477A

GB2177477A - Coupling device for interposition between an impeller and an armature

Info

Publication number: GB2177477A
Application number: GB08516654A
Authority: GB
Inventors: Alfred Milbanke Hudso Palliser
Original assignee: Easthorpe Investments Ltd
Current assignee: Easthorpe Investments Ltd
Priority date: 1985-07-01
Filing date: 1985-07-01
Publication date: 1987-01-21
Also published as: GB8516654D0; IT1191984B; IT8620990A1

Abstract

The device (1) comprises an armature (3) having an engagement tooth (13) shaped to match an elastic engagement tooth (18) rigid with the body of a radial impeller (2). The impeller (2) is removably associable with the armature (3) itself, the latter having at one end thereof elastically deformable elements (11). The impeller further comprises elastic damping means adapted to control, in rotation, the friction with the armature. <IMAGE>

Description

SPECIFICATION Coupling device for interposition between an impeller and an armature This invention relates to a coupling device for interposition between an armature and an impeller, particularly useful with small-size pumps including a radial impeller.

Presently known are devices which may comprise essentially an armature with which there is associated, usually in an unremovable way, an impeller.

The latter receives its motion from the armature by virtue of mutual engagement of two teeth respectively rigid with the impeller and armature.

Such devices are not devoid, however, of drawbacks, one of them being represented by the pump noise produced by the continuous bouncing of the impeller: owing in fact to the high starting torque of the armature, the latter will transfer to the impeller, once the two teeth contact each other, such a shock as to cause subsequent separation of the two teeth for a given time fraction and hence, owing to the friction due to the presence of the fluid, their subsequent coming closer to each other.

Additionally to noise, another drawback is the non-removability of the impeller once it has been associated with the armature.

This invention is directed to eliminate the foregoing drawbacks of known types, by providing a coupling device for interposition between the impeller and armature which allows for proper operation even during the starting stage with consequent silent operation of the pump.

Within the above aim, it is an object of the invention to provide a coupling device for interposition between an impeller and an armature which permits separate maintenance of the two components, while enabling at the same time the obtainment of optimum and fast assembling thereof.

It is a further object of the invention to provide a coupling device for interposition between an impeller and an armature, which is of low cost, and obtainable by utilization of ordinary equipment.

According to one aspect of the invention, there is provided a coupling device for coupling together an armature and an impeller which is characterized in that the armature has means of engagement adapted for co-operation with matchingly shaped engagement means, connected with the body of the impeller and being elastically deformable for damping engagement therebetween, said impeller being removably associable with elastically displaceable elements present on said armature.

Further features and advantages of the invention will be apparent from the description of a preferred embodiment illustrated by way of example in the accompanying drawing sheet, where: Figure 1 is a side view of the armature and impeller as assembled together; Figure 2 is a partly sectional perspective view of the device; Figure 3 is a top plan view of the device; Figure 4 is a bottom plan view of the impeller; Figure 5 is a perspective view of the armature; Figure 6 is a sectional view taken on the line VI VI of Figure 3, where the impeller is shown uncoupled from the armature for clarification purposes; Figure 7 is a sectional view of the armature taken on the section plane VII-VII of Figure 3, the impeller having been omitted for reasons of clarity.

With reference to the foregoing figures, the coupling device 1, particularly useful with small-size pumps, is shown to comprise a radial impeller 2 and an armature 3.

The latter is shown to be composed essentially of a cylindrical body 4 having suitable seats 4a for two permanent magnets 5 opposing each other, from said body 4 there projecting a stem 6 along the longitudinal mid-axis, at that same longitudinal mid-axis there being formed a throughgoing cylindrical seat 7.

At the free ends of the stem 6 there are effected a first cross milling 8 defining two lugs 9 which are elastically deformable in a radial direction, and two more millings 10 which are made diametrically opposite each other on the exterior lateral surface of the stem 6, and extending from the proximity of cylindrical body 4, up to a point proximate to the free end of the stem 6, the lugs 9 defining, accordingly, radially projecting flanges 11.

Thus, between the stem 6 and cylindrical body 4 there is defined a flat annular base 12 whereat there protrudes, radially to the stem 6, a means of abutment engagement 13 formed of a tooth of much lower height than the stem.

The radial impeller 2 is composed essentially of a hollow cylindrical body 14 having an inside diameter approximately equal to the outside diameter of the stem 6, with one end of said body there being made rigid a plurality of radial fins 15 defining essentially parallelepipedal shapes, being alike and having their ends together at the bottom by a flat bannular cap 16.

On the lateral surface of the body 14 there are present, downwardly c the plane of lay of the cap 16, two elastic damping means consisting of two cross millings 17 formed diametrically opposite to each other and affecting the body 14 from the plane of lay of the cap 16 as far as its free end.

The length of the body 14 is such as not to interact with its free end on the engagement means 13, once the impeller has been associated with the armature.

Also rigid with the body 14 is an elastic abutment engagement means consisting of a tooth 18 projecting radially from the cylindrical body 14, said tooth having an essentially frusto/ conical shape of such length and width as to permit rotation of the impeller by interaction with the abutment engagement means 13 rigid with the stem 6.

The coupling device 1 is used as follows: first of all, one should arrange for assembling the impeller 2 and armature 3 together, that operation consisting of inserting the free end of the impeller on the stem 6 of the armature 3.

That operation is made possible by that the lugs 9, which can be deformed elastically in the radial direction towards each other, the flanges 11 having at rest a larger outside diameter than the inside diameter of the body 14.

Thus, when the impeller 2, is fully inserted on the stem 6, the flanges 11 will be free to re-position themselves in the initial condition, by virtue of the elasticity of the lugs 9 causing the rim segments 11 to open outwards, thereby preventing the impeller 2 from coming apart from the armature during rotation thereof.

Thus, once the impeller and the armature have been associated with an ordinary pump the motion between the two will be transferred by virtue of the interaction between the engagement means 13, rigid with the armature 3, and the elastic hooking means, formed of a tooth 18 rigid with the impeller 2.

On starting, due to the considerable torque appliable, the tooth 13 would tend to impart the 18 with such a displacement as to permit, for a given fraction of time, uncoupling between the two; this does not occur thanks to the presence of the damping elastic means (present on the body 14) consisted by the millings 17; the latter permit deformation of the lateral surface of the body 14 and hence form means controlling the friction of the same with the lateral surface of the stem 6.

It has thus been shown that the invention achieves the cited aim and objects, allowing for a proper operation of the pump even at the starting stage, and improving accordingly its silent operation features.

The elastic deformation to which the lugs 9 may be subjected, in addition to permitting rapid, very simple insertion of the impeller onto the stem of the armature without the requirement of any special tools or equipment, also facilitate the rapid, easy removal of the impeller 2 therefore, this arrangement not only allowing optimum assembly of the same, but also optimal maintenance.

Of course, any materials and dimensions may be used depending on requirements.

Claims

1. A coupling device for coupling together an armature and an impeller which is characterised in that the armature has means of engagement adapted for co-operation with matchingly shaped engagement means, connected with the body of the impeller and being elastically deformable for damping engagement therebetween, said impeller being removably associable with elastically displaceable elements present on said armature.

2. A coupling device as in claim 1 comprising an armature which is characterized in that it consists essentially of a hollow cylindrical body having suitable seats for permanent magnets placed diametrically to one another as well as a hollow stem projecting perpendicularly therefrom at the midaxis, at the free end of said stem there being present elastically deformable elements formed of two or more separate longitudinal lugs facing one another and having an outside diameter equal to that of the stem, at the ends of said lugs there protruding radially abutment elements for the impeller consisting of rim segments.

3. A coupling device as in claims 1 and 2 comprising an impeller which is characterized in that it consists of a hollow cylindrical body having an inside diameter approximately equal to the outside one of the armature stem and a length approximately equal to the interspace between the planes of lay of the flanges and the upper one of the armature tooth, said body having at one end a plurality of radial fins radially interconnected at the free ends thereof by a flat annular cap, said body also having elastic damping means consisting of one or more longitudinal millings machined on the lateral surface and extending from the free end of the same to the plane of lay of the annular cap.

4. A coupling device as in claims 1, 2 and 3 comprising an impeller in which a cylindrical body is characterized in that made rigid therewith is an elastic engagement means consisting of a radial tooth, said tooth extending from the place of lay of the annular cap to beyond the free end of the impeller to interact with the engagement means rigid with the armature.

5. A coupling device as in claims 1 and 2 comprising an armature which is characterised in that it has a means of engagement consisting of a tooth placed radially to the stem at its ends made rigid with the cylindrical body.

6. A coupling device as in claims 1 and 4 comprising an impeller the tooth whereof is characterized in that it has an essentially frusto-conical cross-section.

7. An impeller-armature coupling device according to one or more of the preceding claims which is characterized by what is described and illustrated in the accompanying drawing sheet.